The analogy between Iraq and Vietnam has proved to be most compelling to the generals who planned and conducted the Iraq invasion. They kept to themselves their profound disquiet about the rapid rejection of the original plan for invasion that took 10 years to develop, the inadequate downsized force, the absence of preparation for the occupation, and the disastrous decision to disband the Iraqi military.

Almost all voted for Bush in 2000. Serving their civilian neoconservative superiors, they endured contempt. Donald Rumsfeld's closest aide, the undersecretary of defence for intelligence, Stephen Cambone, joked that the army's problems "could be solved by lining up 50 of its generals in the Pentagon and gunning them down", according to Michael Gordon and General Bernard Trainor in their new book on the Iraq invasion, Cobra II. In September 2001, Rumsfeld held a Pentagon meeting where he declared the "bureaucracy" - the career professionals - to be "a serious threat to the security of the United States".

The generals have been wary of engaging in public debate for fear of being misconstrued as political. But they are haunted by Vietnam and deeply influenced by HR McMaster's 1997 book, Dereliction of Duty, which argues that the joint chiefs of staff of the Vietnam era failed in their constitutional responsibility to object strenuously to misguided strategies. (McMaster is a general serving in Iraq.) As the generals have stepped forward to demand Rumsfeld's resignation, they speak in the language of McMaster's book.

On March 19, retired Major General Paul Eaton, who was in charge of training the Iraqi army, called Rumsfeld "incompetent strategically, operationally and tactically". On April 2, retired General Anthony Zinni, former chief of US Central Command, said: "Poor military judgment has been used throughout this mission." On April 9, retired Lieutenant General Gregory Newbold wrote: "I now regret that I did not more openly challenge those who were determined to invade a country whose actions were peripheral to the real threat - al-Qaida."

On April 13, retired Major General John Riggs and Major General Charles Swannack, former commander of the 82nd Airborne, went public. "They only need the military advice when it satisfies their agenda," said Riggs. Swannack emphasised that Rumsfeld bore "culpability" for the abuses at Abu Ghraib.

In response, the Bush administration has mounted a full-scale PR defence. Rumsfeld appeared in the guise of King Solomon on rightwing radio talkshow host Rush Limbaugh's programme: "This, too, will pass." Bush proposed a syllogism: "I'm the decider, and I decide what's best. And what's best is for Don Rumsfeld to remain." But the revolt of the generals, speaking for much of the serving senior officer corps, is unprecedented in scope and depth.

The White House press secretary, Scott McClellan, resigned this week partly to distract attention from Rumsfeld. Clinging to Rumsfeld as indispensable to his strength, Bush reveals his fragility. Their denial extends beyond the realities of Iraq and its history to that of the US. Bush & co disdained nation building as something soft and weak connected to the Clinton presidency, just as they belittled and neglected terrorism as a Clinton obsession before September 11, and as the president dismissed history as weightless.

"History? We don't know. We'll all be dead," Bush remarked in 2003. "We cannot escape history," said Abraham Lincoln. The living president has already sealed his reputation in history.

· Sidney Blumenthal, a former senior adviser to President Clinton, is the author of The Clinton Wars. Email: sidney_blumenthal@yahoo.com